The remainder of the control file contains the field list, which provides information about column formats in the table being loaded. See Chapter 6 for information about that section of the control file.

Comments in the Control File

Comments can appear anywhere in the command section of the file, but they should not appear within the data. Precede any comment with two hyphens, for example:

Specifying Command-Line Parameters in the Control File

The OPTIONS clause is useful when you typically invoke a control file with the same set of options. The OPTIONS clause precedes the LOADDATA statement.

OPTIONS Clause

The OPTIONS clause allows you to specify runtime parameters in the control file, rather than on the command line. The following parameters can be specified using the OPTIONS clause. These parameters are described in greater detail in Chapter 4.

Specifying SQL Strings

Operating System Considerations

The following sections discuss situations in which your course of action may depend on the operating system you are using.

Specifying a Complete Path

If you encounter problems when trying to specify a complete path name, it may be due to an operating system-specific incompatibility caused by special characters in the specification. In many cases, specifying the path name within single quotation marks prevents errors.

Backslash Escape Character

In DDL syntax, you can place a double quotation mark inside a string delimited by double quotation marks by preceding it with the escape character, "\" (if the escape character is allowed on your operating system). The same rule applies when single quotation marks are required in a string delimited by single quotation marks.

For example, homedir\data"norm\mydata contains a double quotation mark. Preceding the double quotation mark with a backslash indicates that the double quotation mark is to be taken literally:

INFILE 'homedir\data\"norm\mydata'

You can also put the escape character itself into a string by entering it twice:

For example:

"so'\"far" or 'so\'"far' is parsed as so'"far
"'so\\far'" or '\'so\\far\'' is parsed as 'so\far'
"so\\\\far" or 'so\\\\far' is parsed as so\\far

Note:

A double quotation mark in the initial position cannot be preceded by an escape character. Therefore, you should avoid creating strings with an initial quotation mark.

Nonportable Strings

There are two kinds of character strings in a SQL*Loader control file that are not portable between operating systems: filename and file processing option strings. When you convert to a different operating system, you will probably need to modify these strings. All other strings in a SQL*Loader control file should be portable between operating systems.

Escaping the Backslash

If your operating system uses the backslash character to separate directories in a path name, and if the version of the Oracle database server running on your operating system implements the backslash escape character for filenames and other nonportable strings, then you must specify double backslashes in your path names and use single quotation marks.

See your Oracle operating system-specific documentation for information about which escape characters are required or allowed.

Escape Character Is Sometimes Disallowed

The version of the Oracle database server running on your operating system may not implement the escape character for nonportable strings. When the escape character is disallowed, a backslash is treated as a normal character, rather than as an escape character (although it is still usable in all other strings). Then path names such as the following can be specified normally:

INFILE 'topdir\mydir\myfile'

Double backslashes are not needed.

Because the backslash is not recognized as an escape character, strings within single quotation marks cannot be embedded inside another string delimited by single quotation marks. This rule also holds for double quotation marks. A string within double quotation marks cannot be embedded inside another string delimited by double quotation marks.

Specifying Datafiles

To specify a datafile that contains the data to be loaded, use the INFILE clause, followed by the filename and optional file processing options string. You can specify multiple files by using multiple INFILE clauses.

Note:

You can also specify the datafile from the command line, using the DATA parameter described in Command-Line Parameters. A filename specified on the command line overrides the first INFILE clause in the control file.

If no filename is specified, the filename defaults to the control filename with an extension or file type of .dat.

If your data is in the control file itself, use an asterisk instead of the filename. If you have data in the control file as well as datafiles, you must specify the asterisk first in order for the data to be read.

os_file_proc_clause

This is the file-processing options string. It specifies the datafile format. It also optimizes datafile reads. The syntax used for this string is specific to your operating system. See Specifying Datafile Format and Buffering.

Examples of INFILE Syntax

The following list shows different ways you can specify INFILE syntax:

Data contained in the control file itself:

INFILE *

Data contained in a file named foo with a default extension of .dat:

INFILE foo

Data contained in a file named datafile.dat with a full path specified:

Specifying Multiple Datafiles

To load data from multiple datafiles in one SQL*Loader run, use an INFILE statement for each datafile. Datafiles need not have the same file processing options, although the layout of the records must be identical. For example, two files could be specified with completely different file processing options strings, and a third could consist of data in the control file.

You can also specify a separate discard file and bad file for each datafile. In such a case, the separate bad files and discard files must be declared immediately after each datafile name. For example, the following excerpt from a control file specifies four datafiles with separate bad and discard files:

For mydat1.dat, both a bad file and discard file are explicitly specified. Therefore both files are created, as needed.

For mydat2.dat, neither a bad file nor a discard file is specified. Therefore, only the bad file is created, as needed. If created, the bad file has the default filename and extension mydat2.bad. The discard file is not created, even if rows are discarded.

For mydat3.dat, the default bad file is created, if needed. A discard file with the specified name (mydat3.dis) is created, as needed.

For mydat4.dat, the default bad file is created, if needed. Because the DISCARDMAX option is used, SQL*Loader assumes that a discard file is required and creates it with the default name mydat4.dsc.

Identifying Data in the Control File with BEGINDATA

If the data is included in the control file itself, then the INFILE clause is followed by an asterisk rather than a filename. The actual data is placed in the control file after the load configuration specifications.

Specify the BEGINDATA parameter before the first data record. The syntax is:

BEGINDATA
data

Keep the following points in mind when using the BEGINDATA parameter:

If you omit the BEGINDATA parameter but include data in the control file, SQL*Loader tries to interpret your data as control information and issues an error message. If your data is in a separate file, do not use the BEGINDATA parameter.

Do not use spaces or other characters on the same line as the BEGINDATA parameter, or the line containing BEGINDATA will be interpreted as the first line of data.

Do not put comments after BEGINDATA, or they will also be interpreted as data.

In this syntax, RECSIZE is the size of a fixed-length record, and BUFFERS is the number of buffers to use for asynchronous I/O.

To declare a file named mydata.dat as a file that contains 80-byte records and instruct SQL*Loader to use 8 I/O buffers, you would use the following control file entry:

INFILE 'mydata.dat' "RECSIZE 80 BUFFERS 8"

For details on the syntax of the file processing options string, see your Oracle operating system-specific documentation.

Note:

This example uses the recommended convention of single quotation marks for filenames and double quotation marks for everything else.

Specifying the Bad File

When SQL*Loader executes, it can create a file called abad file or reject file in which it places records that were rejected because of formatting errors or because they caused Oracle errors. If you have specified that a bad file is to be created, the following applies:

If one or more records are rejected, the bad file is created and the rejected records are logged.

If no records are rejected, then the bad file is not created. When this occurs, you must reinitialize the bad file for the next run.

If the bad file is created, it overwrites any existing file with the same name; ensure that you do not overwrite a file you wish to retain.

Note:

On some systems, a new version of the file is created if a file with the same name already exists. See your Oracle operating system-specific documentation to find out if this is the case on your system.

To specify the name of the bad file, use the BADFILE parameter (or BADDN for DB2 compatibility), followed by the bad file filename. If you do not specify a name for the bad file, the name defaults to the name of the datafile with an extension or file type of .bad. You can also specify the bad file from the command line with the BAD parameter described in Command-Line Parameters.

A filename specified on the command line is associated with the first INFILE or INDDN clause in the control file, overriding any bad file that may have been specified as part of that clause.

The bad file is created in the same record and file format as the datafile so that the data can be reloaded after making corrections. For datafiles in stream record format, the record terminator that is found in the datafile is also used in the bad file.

(Use BADDN when DB2 compatibility is required.) This parameter specifies that a filename for the bad file follows.

bad_filename

Any valid filename specification for your platform.

Any spaces or punctuation marks in the filename must be enclosed in single quotation marks.

Examples of Specifying a Bad File Name

To specify a bad file with filename ugh and default file extension or file type of .bad, enter:

BADFILE ugh

To specify a bad file with filename bad0001 and file extension or file type of .rej, enter either of the following lines:

BADFILE bad0001.rej
BADFILE '/REJECT_DIR/bad0001.rej'

How Bad Files Are Handled with LOBFILEs and SDFs

Data from LOBFILEs and SDFs is not written to a bad file when there are rejected rows. If there is an error loading a LOB, the row is not rejected. Rather, the LOB column is left empty (not null with a length of zero (0) bytes). However, when the LOBFILE is being used to load an XML column and there is an error loading this LOB data, then the XML column is left as null.

Criteria for Rejected Records

A record can be rejected for the following reasons:

Upon insertion, the record causes an Oracle error (such as invalid data for a given datatype).

The record is formatted incorrectly so that SQL*Loader cannot find field boundaries.

The record violates a constraint or tries to make a unique index non-unique.

If the data can be evaluated according to the WHEN clause criteria (even with unbalanced delimiters), then it is either inserted or rejected.

Neither a conventional path nor a direct path load will write a row to any table if it is rejected because of reason number 2 in the previous list.

Additionally, a conventional path load will not write a row to any tables if reason number 1 or 3 in the previous list is violated for any one table. The row is rejected for that table and written to the reject file.

Specifying the Discard File

During SQL*Loader execution, it can create a discard file for records that do not meet any of the loading criteria. The records contained in this file are called discarded records. Discarded records do not satisfy any of the WHEN clauses specified in the control file. These records differ from rejected records. Discarded records do not necessarily have any bad data. No insert is attempted on a discarded record.

A discard file is created according to the following rules:

You have specified a discard filename and one or more records fail to satisfy all of the WHEN clauses specified in the control file. (If the discard file is created, it overwrites any existing file with the same name, so be sure that you do not overwrite any files you wish to retain.)

If no records are discarded, then a discard file is not created.

To create a discard file, use any of the following syntax:

In a Control File

On the Command Line

DISCARDFILEfilename

DISCARD

DISCARDDNfilename(DB2)

DISCARDMAX

DISCARDS

DISCARDMAX

You can specify the discard file directly by specifying its name, or indirectly by specifying the maximum number of discards.

The discard file is created in the same record and file format as the datafile. For datafiles in stream record format, the same record terminator that is found in the datafile is also used in the discard file.

Specifying the Discard File in the Control File

To specify the name of the file, use the DISCARDFILE or DISCARDDN (for DB2-compatibility) parameter, followed by the filename.

(Use DISCARDDN when DB2 compatibility is required.) This parameter specifies that a discard filename follows.

discard_filename

Any valid filename specification for your platform.

Any spaces or punctuation marks in the filename must be enclosed in single quotation marks.

The default filename is the name of the datafile, and the default file extension or file type is .dsc. A discard filename specified on the command line overrides one specified in the control file. If a discard file with that name already exists, it is either overwritten or a new version is created, depending on your operating system.

Specifying the Discard File from the Command Line

See DISCARD (filename) for information on how to specify a discard file from the command line.

A filename specified on the command line overrides any discard file that you may have specified in the control file.

Examples of Specifying a Discard File Name

The following list shows different ways you can specify a name for the discard file from within the control file:

To specify a discard file with filename circular and default file extension or file type of .dsc:

DISCARDFILEcircular

To specify a discard file named notappl with the file extension or file type of .may:

DISCARDFILE notappl.may

To specify a full path to the discard file forget.me:

DISCARDFILE '/discard_dir/forget.me'

Criteria for Discarded Records

If there is no INTO TABLE clause specified for a record, the record is discarded. This situation occurs when every INTO TABLE clause in the SQL*Loader control file has a WHEN clause and, either the record fails to match any of them, or all fields are null.

No records are discarded if an INTO TABLE clause is specified without a WHEN clause. An attempt is made to insert every record into such a table. Therefore, records may be rejected, but none are discarded.

Limiting the Number of Discarded Records

When the discard limit (specified with integer) is reached, processing of the datafile terminates and continues with the next datafile, if one exists.

You can specify a different number of discards for each datafile. Or, if you specify the number of discards only once, then the maximum number of discards specified applies to all files.

If you specify a maximum number of discards, but no discard filename, SQL*Loader creates a discard file with the default filename and file extension or file type.

Handling Different Character Encoding Schemes

SQL*Loader supports different character encoding schemes (called character sets, or code pages). SQL*Loader uses features of Oracle's Globalization Support technology to handle the various single-byte and multibyte character encoding schemes available today.

In general, loading shift-sensitive character data can be much slower than loading simple ASCII or EBCDIC data. The fastest way to load shift-sensitive character data is to use fixed-position fields without delimiters. To improve performance, remember the following points:

The field data must have an equal number of shift-out/shift-in bytes.

The field must start and end in single-byte mode.

It is acceptable for the first byte to be shift-out and the last byte to be shift-in.

The first and last characters cannot be multibyte.

If blanks are not preserved and multibyte-blank-checking is required, a slower path is used. This can happen when the shift-in byte is the last byte of a field after single-byte blank stripping is performed.

The following sections provide a brief introduction to some of the supported character encoding schemes.

Multibyte (Asian) Character Sets

Multibyte character sets support Asian languages. Data can be loaded in multibyte format, and database object names (fields, tables, and so on) can be specified with multibyte characters. In the control file, comments and object names can also use multibyte characters.

Unicode Character Sets

SQL*Loader supports loading data that is in a Unicode character set.

Unicode is a universal encoded character set that supports storage of information from most languages in a single character set. Unicode provides a unique code value for every character, regardless of the platform, program, or language. There are two different encodings for Unicode, UTF-16 and UTF-8.

Note:

In this manual, you will see the terms UTF-16 and UTF16 both used. The term UTF-16 is a general reference to UTF-16 encoding for Unicode. The term UTF16 (no hyphen) is the specific name of the character set and is what you should specify for the CHARACTERSET parameter when you want to use UTF-16 encoding. This also applies to UTF-8 and UTF8.

The UTF-16 Unicode encoding is a fixed-width multibyte encoding in which the character codes 0x0000 through 0x007F have the same meaning as the single-byte ASCII codes 0x00 through 0x7F.

The UTF-8 Unicode encoding is a variable-width multibyte encoding in which the character codes 0x00 through 0x7F have the same meaning as ASCII. A character in UTF-8 can be 1 byte, 2 bytes, or 3 bytes long.

Database Character Sets

The Oracle database server uses the database character set for data stored in SQL CHAR datatypes (CHAR,VARCHAR2,CLOB, and LONG), for identifiers such as table names, and for SQL statements and PL/SQL source code. Only single-byte character sets and varying-width character sets that include either ASCII or EBCDIC characters are supported as database character sets. Multibyte fixed-width character sets (for example, AL16UTF16) are not supported as the database character set.

An alternative character set can be used in the database for data stored in SQL NCHAR datatypes (NCHAR,NVARCHAR, and NCLOB). This alternative character set is called the database national character set. Only Unicode character sets are supported as the database national character set.

Datafile Character Sets

By default, the datafile is in the character set as defined by the NLS_LANG parameter. The datafile character sets supported with NLS_LANG are the same as those supported as database character sets. SQL*Loader supports all Oracle-supported character sets in the datafile (even those not supported as database character sets).

For example, SQL*Loader supports multibyte fixed-width character sets (such as AL16UTF16 and JA16EUCFIXED) in the datafile. SQL*Loader also supports UTF-16 encoding with little endian byte ordering. However, the Oracle database server supports only UTF-16 encoding with big endian byte ordering (AL16UTF16) and only as a database national character set, not as a database character set.

The character set of the datafile can be set up by using the NLS_LANG parameter or by specifying a SQL*Loader CHARACTERSET parameter.

Input Character Conversion

The default character set for all datafiles, if the CHARACTERSET parameter is not specified, is the session character set defined by the NLS_LANG parameter. The character set used in input datafiles can be specified with the CHARACTERSET parameter.

SQL*Loader has the capacity to automatically convert data from the datafile character set to the database character set or the database national character set, when they differ.

When data character set conversion is required, the target character set should be a superset of the source datafile character set. Otherwise, characters that have no equivalent in the target character set are converted to replacement characters, often a default character such as a question mark (?). This causes loss of data.

The sizes of the database character types CHAR and VARCHAR2 can be specified in bytes (byte-length semantics) or in characters (character-length semantics). If they are specified in bytes, and data character set conversion is required, the converted values may take more bytes than the source values if the target character set uses more bytes than the source character set for any character that is converted. This will result in the following error message being reported if the larger target value exceeds the size of the database column:

ORA-01401: inserted value too large for column

You can avoid this problem by specifying the database column size in characters and by also using character sizes in the control file to describe the data. Another way to avoid this problem is to ensure that the maximum column size is large enough, in bytes, to hold the converted value.

CHARACTERSET Parameter

Specifying the CHARACTERSET parameter tells SQL*Loader the character set of the input datafile. The default character set for all datafiles, if the CHARACTERSET parameter is not specified, is the session character set defined by the NLS_LANG parameter. Only character data (fields in the SQL*Loader datatypes CHAR,VARCHAR,VARCHARC, numeric EXTERNAL, and the datetime and interval datatypes) is affected by the character set of the datafile.

The CHARACTERSET syntax is as follows:

CHARACTERSET char_set_name

The char_set_name variable specifies the character set name. Normally, the specified name must be the name of an Oracle-supported character set.

For UTF-16 Unicode encoding, use the name UTF16 rather than AL16UTF16. AL16UTF16, which is the supported Oracle character set name for UTF-16 encoded data, is only for UTF-16 data that is in big endian byte order. However, because you are allowed to set up data using the byte order of the system where you create the datafile, the data in the datafile can be either big endian or little endian. Therefore, a different character set name (UTF16) is used. The character set name AL16UTF16 is also supported. But if you specify AL16UTF16 for a datafile that has little endian byte order, SQL*Loader issues a warning message and processes the datafile as big endian.

The CHARACTERSET parameter can be specified for primary datafiles as well as LOBFILEs and SDFs. It is possible to specify different character sets for different input datafiles. A CHARACTERSET parameter specified before the INFILE parameter applies to the entire list of primary datafiles. If the CHARACTERSET parameter is specified for primary datafiles, the specified value will also be used as the default for LOBFILEs and SDFs. This default setting can be overridden by specifying the CHARACTERSET parameter with the LOBFILE or SDF specification.

The character set specified with the CHARACTERSET parameter does not apply to data in the control file (specified with INFILE). To load data in a character set other than the one specified for your session by the NLS_LANG parameter, you must place the data in a separate datafile.

Control File Character Set

The SQL*Loader control file itself is assumed to be in the character set specified for your session by the NLS_LANG parameter. If the control file character set is different from the datafile character set, keep the following issue in mind. Delimiters and comparison clause values specified in the SQL*Loader control file as character strings are converted from the control file character set to the datafile character set before any comparisons are made. To ensure that the specifications are correct, you may prefer to specify hexadecimal strings, rather than character string values.

If hexadecimal strings are used with a datafile in the UTF-16 Unicode encoding, the byte order is different on a big endian versus a little endian system. For example, "," (comma) in UTF-16 on a big endian system is X'002c'. On a little endian system it is X'2c00'. SQL*Loader requires that you always specify hexadecimal strings in big endian format. If necessary, SQL*Loader swaps the bytes before making comparisons. This allows the same syntax to be used in the control file on both a big endian and a little endian system.

Record terminators for datafiles that are in stream format in the UTF-16 Unicode encoding default to "\n" in UTF-16 (that is, 0x000A on a big endian system and 0x0A00 on a little endian system). You can override these default settings by using the "STR 'char_str'" or the "STR x'hex_str'" specification on the INFILE line. For example, you could use either of the following to specify that 'ab' is to be used as the record terminator, instead of '\n'.

INFILE myfile.dat "STR 'ab'"
INFILE myfile.dat "STR x'00410042'"

Any data included after the BEGINDATA statement is also assumed to be in the character set specified for your session by the NLS_LANG parameter.

For the SQL*Loader datatypes (CHAR,VARCHAR,VARCHARC,DATE, and EXTERNAL numerics), SQL*Loader supports lengths of character fields that are specified in either bytes (byte-length semantics) or characters (character-length semantics). For example, the specification CHAR(10) in the control file can mean 10 bytes or 10 characters. These are equivalent if the datafile uses a single-byte character set. However, they are often different if the datafile uses a multibyte character set.

To avoid insertion errors caused by expansion of character strings during character set conversion, use character-length semantics in both the datafile and the target database columns.

Character-Length Semantics

Byte-length semantics are the default for all datafiles except those that use the UTF16 character set (which uses character-length semantics by default). To override the default you can specify CHAR or CHARACTER, as shown in the following syntax:

The LENGTH parameter is placed after the CHARACTERSET parameter in the SQL*Loader control file. The LENGTH parameter applies to the syntax specification for primary datafiles as well as to LOBFILEs and secondary datafiles (SDFs). It is possible to specify different length semantics for different input datafiles. However, a LENGTH specification before the INFILE parameters applies to the entire list of primary datafiles. The LENGTH specification specified for the primary datafile is used as the default for LOBFILEs and SDFs. You can override that default by specifying LENGTH with the LOBFILE or SDF specification. Unlike the CHARACTERSET parameter, the LENGTH parameter can also apply to data contained within the control file itself (that is, INFILE * syntax).

You can specify CHARACTER instead of CHAR for the LENGTH parameter.

If character-length semantics are being used for a SQL*Loader datafile, then the following SQL*Loader datatypes will use character-length semantics:

CHAR

VARCHAR

VARCHARC

DATE

EXTERNAL numerics (INTEGER, FLOAT, DECIMAL, and ZONED)

For the VARCHAR datatype, the length subfield is still a binary SMALLINT length subfield, but its value indicates the length of the character string in characters.

The following datatypes use byte-length semantics even if character-length semantics are being used for the datafile, because the data is binary, or is in a special binary-encoded form in the case of ZONED and DECIMAL:

INTEGER

SMALLINT

FLOAT

DOUBLE

BYTEINT

ZONED

DECIMAL

RAW

VARRAW

VARRAWC

GRAPHIC

GRAPHIC EXTERNAL

VARGRAPHIC

The start and end arguments to the POSITION parameter are interpreted in bytes, even if character-length semantics are in use in a datafile. This is necessary to handle datafiles that have a mix of data of different datatypes, some of which use character-length semantics, and some of which use byte-length semantics. It is also needed to handle position with the VARCHAR datatype, which has a SMALLINT length field and then the character data. The SMALLINT length field takes up a certain number of bytes depending on the system (usually 2 bytes), but its value indicates the length of the character string in characters.

Character-length semantics in the datafile can be used independent of whether or not character-length semantics are used for the database columns. Therefore, the datafile and the database columns can use either the same or different length semantics.

Continuing an Interrupted Load

If SQL*Loader runs out of space for data rows or index entries, the load is discontinued. (For example, the table might reach its maximum number of extents.) Discontinued loads can be continued after more space is made available.

Status of Tables and Indexes After an Interrupted Load

When a load is discontinued, any data already loaded remains in the tables, and the tables are left in a valid state. If the conventional path is used, all indexes are left in a valid state.

If the direct path load method is used, any indexes that run out of space are left in an unusable state. You must drop these indexes before the load can continue. You can re-create the indexes either before continuing or after the load completes.

Other indexes are valid if no other errors occurred. See Indexes Left in Unusable State for other reasons why an index might be left in an unusable state.

Using the Log File to Determine Load Status

The SQL*Loader log file tells you the state of the tables and indexes and the number of logical records already read from the input datafile. Use this information to resume the load where it left off.

Continuing Single-Table Loads

To continue a discontinued direct or conventional path load involving only one table, specify the number of logical records to skip with the command-line parameter SKIP. If the SQL*Loader log file says that 345 records were previously read, then the command to continue would look like this:

sqlldr USERID=scott/tiger CONTROL=fast1.ctl DIRECT=true SKIP=345

Continuing Multiple-Table Conventional Loads

It is not possible for multiple tables in a conventional path load to become unsynchronized. Therefore, a multiple-table conventional path load can also be continued with the command-line parameter SKIP. Use the same procedure that you would use for single-table loads, as described in Continuing Single-Table Loads.

Continuing Multiple-Table Direct Loads

If SQL*Loader cannot finish a multiple-table direct path load, the number of logical records processed could be different for each table. If so, the tables are not synchronized and continuing the load is slightly more complex.

To continue a discontinued direct path load involving multiple tables, inspect the SQL*Loader log file to find out how many records were loaded into each table.

If the numbers are the same, you can use the same procedure that you would use for single-table loads, as described in Continuing Single-Table Loads.

If the numbers are different, use the CONTINUE_LOAD parameter and specify SKIP at the table level, instead of at the load level. These statements exist to handle unsynchronized interrupted loads.

In this case, do not specify the following at the start of the control file:

LOAD DATA...

Instead, at the start of the control file, specify:

CONTINUE_LOAD DATA

Then, for each INTO TABLE clause, specify the number of logical records to skip for that table, using the SKIP parameter:

...
INTO TABLE emp
SKIP 2345
...
INTO TABLE dept
SKIP 514
...

Combining SKIP and CONTINUE_LOAD

The CONTINUE_LOAD parameter is only needed after a direct load failure because multiple table loads cannot become unsynchronized when using the conventional path.

If you specify CONTINUE_LOAD, you cannot use the command-line parameter SKIP. You must use the table-level SKIP clause. If you specify LOAD, you can optionally use the command-line parameter SKIP, but you cannot use the table-level SKIP clause.

Assembling Logical Records from Physical Records

Because Oracle9i supports user-defined record sizes larger than 64 KB (see READSIZE (read buffer size)), the need to break up logical records into multiple physical records is reduced. However, there may still be situations in which you may want to do so. At some point, when you want to combine those multiple physical records back into one logical record, you can use one of the following clauses, depending on your data:

CONCATENATE

CONTINUEIF

Using CONCATENATE to Assemble Logical Records

Use CONCATENATE when SQL*Loader should always add the same number of physical records to form one logical record. In the following example, integer specifies the number of physical records to combine.

CONCATENATE integer

Using CONTINUEIF to Assemble Logical Records

Use CONTINUEIF if the number of physical records to be continued varies. The parameter CONTINUEIF is followed by a condition that is evaluated for each physical record, as it is read. For example, two records might be combined if a pound sign (#) were in byte position 80 of the first record. If any other character were there, the second record would not be added to the first.

If the condition is true in the current record, then the next physical record is read and concatenated to the current physical record, continuing until the condition is false. If the condition is false, then the current physical record becomes the last physical record of the current logical record. THIS is the default.

NEXT

If the condition is true in the next record, then the current physical record is concatenated to the current logical record, continuing until the condition is false.

operator

The supported operators are equal and not equal.

For the equal operator, the field and comparison string must match exactly for the condition to be true. For the not equal operator, they may differ in any character.

LAST

This test is similar to THIS, but the test is always against the last nonblank character. If the last nonblank character in the current physical record meets the test, then the next physical record is read and concatenated to the current physical record, continuing until the condition is false. If the condition is false in the current record, then the current physical record is the last physical record of the current logical record.

pos_spec

Specifies the starting and ending column numbers in the physical record.

Column numbers start with 1. Either a hyphen or a colon is acceptable (start-end or start:end).

If you omit end, the length of the continuation field is the length of the byte string or character string. If you use end, and the length of the resulting continuation field is not the same as that of the byte string or the character string, the shorter one is padded. Character strings are padded with blanks, hexadecimal strings with zeros.

str

A string of characters to be compared to the continuation field defined by start and end, according to the operator. The string must be enclosed in double or single quotation marks. The comparison is made character by character, blank padding on the right if necessary.

X'hex-str'

A string of bytes in hexadecimal format used in the same way as str. X'1FB033 would represent the three bytes with values 1F, B0, and 33 (hexadecimal).

PRESERVE

Includes 'char_string' or X'hex_string' in the logical record. The default is to exclude them.

Note:

The positions in the CONTINUEIF clause refer to positions in each physical record. This is the only time you refer to positions in physical records. All other references are to logical records.

If the PRESERVE parameter is not used, the continuation field is removed from all physical records when the logical record is assembled. That is, data values are allowed to span the records with no extra characters (continuation characters) in the middle.

If the PRESERVE parameter is used, the continuation field is kept in all physical records when the logical record is assembled.

Example 5-2 through Example 5-5 show the use of CONTINUEIF THIS and CONTINUEIF NEXT, with and without the PRESERVE parameter.

Example 5-2 CONTINUEIF THIS Without the PRESERVE Parameter

Assume that you have physical records 14 bytes long and that a period represents a space:

Specifying Table Names

The INTOTABLE clause of the LOADDATA statement allows you to identify tables, fields, and datatypes. It defines the relationship between records in the datafile and tables in the database. The specification of fields and datatypes is described in later sections.

INTO TABLE Clause

Among its many functions, the INTOTABLE clause allows you to specify the table into which you load data. To load multiple tables, you include one INTOTABLE clause for each table you wish to load.

To begin an INTOTABLE clause, use the keywords INTOTABLE, followed by the name of the Oracle table that is to receive the data.

The table must already exist. The table name should be enclosed in double quotation marks if it is the same as any SQL or SQL*Loader reserved keyword, if it contains any special characters, or if it is case sensitive.

INTO TABLE scott."CONSTANT"
INTO TABLE scott."Constant"
INTO TABLE scott."-CONSTANT"

The user must have INSERT privileges for the table being loaded. If the table is not in the user's schema, then the user must either use a synonym to reference the table or include the schema name as part of the table name (for example, scott.emp).

Table-Specific Loading Method

The INTOTABLE clause may include a table-specific loading method (INSERT, APPEND,REPLACE, or TRUNCATE) that applies only to that table. Specifying one of these methods within the INTO TABLE clause overrides the global table-loading method. The global table-loading method is INSERT, by default, unless a different method was specified before any INTOTABLE clauses. The following sections discuss using these options to load data into empty and nonempty tables.

Loading Data into Empty Tables

If the tables you are loading into are empty, use the INSERT option.

INSERT

This is SQL*Loader's default method. It requires the table to be empty before loading. SQL*Loader terminates with an error if the table contains rows. Case Study 1: Loading Variable-Length Data provides an example.

Loading Data into Nonempty Tables

If the tables you are loading into already contain data, you have three options:

APPEND

REPLACE

TRUNCATE

Caution:

When REPLACE or TRUNCATE is specified, the entire table is replaced, not just individual rows. After the rows are successfully deleted, a commit is issued. You cannot recover the data that was in the table before the load, unless it was saved with Export or a comparable utility.

Note:

This section corresponds to the DB2 keyword RESUME; users of DB2 should also refer to the description of RESUME in Appendix B.

APPEND

If data already exists in the table, SQL*Loader appends the new rows to it. If data does not already exist, the new rows are simply loaded. You must have SELECT privilege to use the APPEND option. Case Study 3: Loading a Delimited, Free-Format File provides an example.

The row deletes cause any delete triggers defined on the table to fire. If DELETE CASCADE has been specified for the table, then the cascaded deletes are carried out. For more information on cascaded deletes, see the information about data integrity in Oracle9i Database Concepts.

Updating Existing Rows

The REPLACE method is a table replacement, not a replacement of individual rows. SQL*Loader does not update existing records, even if they have null columns. To update existing rows, use the following procedure:

TRUNCATE

The SQL TRUNCATE statement quickly and efficiently deletes all rows from a table or cluster, to achieve the best possible performance. For the TRUNCATE statement to operate, the table's referential integrity constraints must first be disabled. If they have not been disabled, SQL*Loader returns an error.

Once the integrity constraints have been disabled, DELETE CASCADE is no longer defined for the table. If the DELETE CASCADE functionality is needed, then the contents of the table must be manually deleted before the load begins.

The table must be in your schema, or you must have the DROP ANY TABLE privilege.

Using the WHEN Clause with LOBFILEs and SDFs

If a record with a LOBFILE or SDF is discarded, SQL*Loader skips the corresponding data in that LOBFILE or SDF.

Specifying Default Data Delimiters

If all data fields are terminated similarly in the datafile, you can use the FIELDS clause to indicate the default delimiters. The syntax for the fields_spec,termination_spec, and enclosure_spec clauses is as follows:

Handling Short Records with Missing Data

When the control file definition specifies more fields for a record than are present in the record, SQL*Loader must determine whether the remaining (specified) columns should be considered null or whether an error should be generated.

If the control file definition explicitly states that a field's starting position is beyond the end of the logical record, then SQL*Loader always defines the field as null. If a field is defined with a relative position (such as dname and loc in the following example), and the record ends before the field is found, then SQL*Loader could either treat the field as null or generate an error. SQL*Loader uses the presence or absence of the TRAILING NULLCOLS clause to determine the course of action.

SINGLEROW Option

The SINGLEROW option is intended for use during a direct path load with APPEND on systems with limited memory, or when loading a small number of records into a large table. This option inserts each index entry directly into the index, one record at a time.

By default, SQL*Loader does not use SINGLEROW to append records to a table. Instead, index entries are put into a separate, temporary storage area and merged with the original index at the end of the load. This method achieves better performance and produces an optimal index, but it requires extra storage space. During the merge, the original index, the new index, and the space for new entries all simultaneously occupy storage space.

With the SINGLEROW option, storage space is not required for new index entries or for a new index. The resulting index may not be as optimal as a freshly sorted one, but it takes less space to produce. It also takes more time because additional UNDO information is generated for each index insert. This option is suggested for use when either of the following situations exists:

Available storage is limited.

The number of records to be loaded is small compared to the size of the table (a ratio of 1:20 or less is recommended).

Benefits of Using Multiple INTO TABLE Clauses

Multiple INTOTABLE clauses allow you to:

Load data into different tables

Extract multiple logical records from a single input record

Distinguish different input record formats

Distinguish different input row object subtypes

In the first case, it is common for the INTO TABLE clauses to refer to the same table. This section illustrates the different ways to use multiple INTO TABLE clauses and shows you how to use the POSITION parameter.

Note:

A key point when using multiple INTO TABLE clauses is that field scanning continues from where it left off when a new INTO TABLE clause is processed. The remainder of this section details important ways to make use of that behavior. It also describes alternative ways using fixed field locations or the POSITION parameter.

Extracting Multiple Logical Records

Some data storage and transfer media have fixed-length physical records. When the data records are short, more than one can be stored in a single, physical record to use the storage space efficiently.

In this example, SQL*Loader treats a single physical record in the input file as two logical records and uses two INTOTABLE clauses to load the data into the emp table. For example, assume the data is as follows:

Relative Positioning Based on Delimiters

The same record could be loaded with a different specification. The following control file uses relative positioning instead of fixed positioning. It specifies that each field is delimited by a single blank (" ") or with an undetermined number of blanks and tabs (WHITESPACE):

The important point in this example is that the second empno field is found immediately after the first ename, although it is in a separate INTO TABLE clause. Field scanning does not start over from the beginning of the record for a new INTO TABLE clause. Instead, scanning continues where it left off.

A record ID field distinguishes between the two formats. Department records have a 1 in the first column, while employee records have a 2. The following control file uses exact positioning to load this data:

The POSITION parameter in the second INTO TABLE clause is necessary to load this data correctly. It causes field scanning to start over at column 1 when checking for data that matches the second format. Without it, SQL*Loader would look for the recid field after dname.

Distinguishing Different Input Row Object Subtypes

A single datafile may contain records made up of row objects inherited from the same base row object type. For example, consider the following simple object type and object table definitions in which a nonfinal base object type is defined along with two object subtypes that inherit from the base type:

The following input datafile contains a mixture of these row objects subtypes. A type ID field distinguishes between the three subtypes. person_t objects have a P in the first column, employee_t objects have an E, and student_t objects have an S.

The following control file uses relative positioning based on the POSITION parameter to load this data. Note the use of the TREATAS clause with a specific object type name. This informs SQL*Loader that all input row objects for the object table will conform to the definition of the named object type.

Loading Data into Multiple Tables

Summary

Multiple INTO TABLE clauses allow you to extract multiple logical records from a single input record and recognize different record formats in the same file.

For delimited data, proper use of the POSITION parameter is essential for achieving the expected results.

When the POSITION parameter is not used, multiple INTO TABLE clauses process different parts of the same (delimited data) input record, allowing multiple tables to be loaded from one record. When the POSITION parameter is used, multiple INTO TABLE clauses can process the same record in different ways, allowing multiple formats to be recognized in one input file.

Bind Arrays and Conventional Path Loads

SQL*Loader uses the SQL array-interface option to transfer data to the database. Multiple rows are read at one time and stored in the bind array. When SQL*Loader sends the Oracle database an INSERT command, the entire array is inserted at one time. After the rows in the bind array are inserted, a COMMIT is issued.

The determination of bind array size pertains to SQL*Loader's conventional path option. It does not apply to the direct path load method because a direct path load uses the Direct Path API, rather than Oracle's SQL interface.

Size Requirements for Bind Arrays

The bind array must be large enough to contain a single row. If the maximum row length exceeds the size of the bind array, as specified by the BINDSIZE parameter, SQL*Loader generates an error. Otherwise, the bind array contains as many rows as can fit within it, up to the limit set by the value of the ROWS parameter.

Although the entire bind array need not be in contiguous memory, the buffer for each field in the bind array must occupy contiguous memory. If the operating system cannot supply enough contiguous memory to store a field, SQL*Loader generates an error.

Performance Implications of Bind Arrays

Large bind arrays minimize the number of calls to the Oracle database server and maximize performance. In general, you gain large improvements in performance with each increase in the bind array size up to 100 rows. Increasing the bind array size to be greater than 100 rows generally delivers more modest improvements in performance. The size (in bytes) of 100 rows is typically a good value to use.

In general, any reasonably large size permits SQL*Loader to operate effectively. It is not usually necessary to perform the detailed calculations described in this section. Read this section when you need maximum performance or an explanation of memory usage.

Specifying Number of Rows Versus Size of Bind Array

When you specify a bind array size using the command-line parameter BINDSIZE (see BINDSIZE (maximum size)) or the OPTIONS clause in the control file (see OPTIONS Clause), you impose an upper limit on the bind array. The bind array never exceeds that maximum.

As part of its initialization, SQL*Loader determines the size in bytes required to load a single row. If that size is too large to fit within the specified maximum, the load terminates with an error.

SQL*Loader then multiplies that size by the number of rows for the load, whether that value was specified with the command-line parameter ROWS (see ROWS (rows per commit)) or the OPTIONS clause in the control file (see OPTIONS Clause).

If that size fits within the bind array maximum, the load continues--SQL*Loader does not try to expand the number of rows to reach the maximum bind array size. If the number of rows and the maximum bind array size are both specified, SQL*Loader always uses the smaller value for the bind array.

If the maximum bind array size is too small to accommodate the initial number of rows, SQL*Loader uses a smaller number of rows that fits within the maximum.

Calculations to Determine Bind Array Size

The bind array's size is equivalent to the number of rows it contains times the maximum length of each row. The maximum length of a row is equal to the sum of the maximum field lengths, plus overhead, as follows:

Many fields do not vary in size. These fixed-length fields are the same for each loaded row. For these fields, the maximum length of the field is the field size, in bytes, as described in SQL*Loader Datatypes. There is no overhead for these fields.

The fields that can vary in size from row to row are:

CHAR

DATE

INTERVALDAYTOSECOND

INTERVALDAYTOYEAR

LONGVARRAW

numeric EXTERNAL

TIME

TIMESTAMP

TIMEWITHTIMEZONE

TIMESTAMPWITHTIMEZONE

VARCHAR

VARCHARC

VARGRAPHIC

VARRAW

VARRAWC

The maximum length of these datatypes is described in SQL*Loader Datatypes. The maximum lengths describe the number of bytes that the fields can occupy in the input data record. That length also describes the amount of storage that each field occupies in the bind array, but the bind array includes additional overhead for fields that can vary in size.

When the character datatypes (CHAR, DATE, and numeric EXTERNAL) are specified with delimiters, any lengths specified for these fields are maximum lengths. When specified without delimiters, the size in the record is fixed, but the size of the inserted field may still vary, due to whitespace trimming. So internally, these datatypes are always treated as varying-length fields--even when they are fixed-length fields.

A length indicator is included for each of these fields in the bind array. The space reserved for the field in the bind array is large enough to hold the longest possible value of the field. The length indicator gives the actual length of the field for each row.

Note:

In conventional path loads, LOBFILEs are not included when allocating the size of a bind array.

Determining the Size of the Length Indicator

On most systems, the size of the length indicator is 2 bytes. On a few systems, it is 3 bytes. To determine its size, use the following control file:

This control file loads a 1-byte CHAR using a 1-row bind array. In this example, no data is actually loaded because a conversion error occurs when the character a is loaded into a numeric column (deptno). The bind array size shown in the log file, minus one (the length of the character field) is the value of the length indicator.

Note:

A similar technique can determine bind array size without doing any calculations. Run your control file without any data and with ROWS=1 to determine the memory requirements for a single row of data. Multiply by the number of rows you want in the bind array to determine the bind array size.

Calculating the Size of Field Buffers

Table 5-1 through Table 5-4 summarize the memory requirements for each datatype. "L" is the length specified in the control file. "P" is precision. "S" is the size of the length indicator. For more information on these values, see SQL*Loader Datatypes.

Table 5-4 Variable-Length Fields

Minimizing Memory Requirements for Bind Arrays

Pay particular attention to the default sizes allocated for VARCHAR, VARGRAPHIC, and the delimited forms of CHAR, DATE, and numeric EXTERNAL fields. They can consume enormous amounts of memory--especially when multiplied by the number of rows in the bind array. It is best to specify the smallest possible maximum length for these fields. Consider the following example:

CHAR(10) TERMINATED BY ","

With byte-length semantics, this example uses (10 + 2) * 64 = 768 bytes in the bind array, assuming that the length indicator is 2 bytes long and that 64 rows are loaded at a time.

With character-length semantics, the same example uses ((10 * s) + 2) * 64 bytes in the bind array, where "s" is the maximum size in bytes of a character in the datafile character set.

Now consider the following example:

CHAR TERMINATED BY ","

Regardless of whether byte-length semantics or character-length semantics are used, this example uses (255 + 2) * 64 = 16,448 bytes, because the default maximum size for a delimited field is 255 bytes. This can make a considerable difference in the number of rows that fit into the bind array.

Calculating Bind Array Size for Multiple INTO TABLE Clauses

When calculating a bind array size for a control file that has multiple INTOTABLE clauses, calculate as if the INTOTABLE clauses were not present. Imagine all of the fields listed in the control file as one, long data structure--that is, the format of a single row in the bind array.

If the same field in the data record is mentioned in multiple INTOTABLE clauses, additional space in the bind array is required each time it is mentioned. It is especially important to minimize the buffer allocations for such fields.

Note:

Generated data is produced by the SQL*Loader functions CONSTANT, EXPRESSION, RECNUM, SYSDATE, and SEQUENCE. Such generated data does not require any space in the bind array.